Multi-row rolling mills, methods of operating these mills, and rolling equipment using the mills

ABSTRACT

A multi-row rolling mill has in one housing at least two groups of rolls including at least one pair of work rolls, and constructed so that when the workpiece to be rolled is passed one time, it can be rolled using said respective work rolls. The multi-row rolling mill is characterized in that it is provided with a means for removing the workpiece if the workpiece stops moving between said roll groups.

BACKGROUND OF INVENTION

This application claims the priority of Japanese Application No.2001-314967, filed in Japan on Oct. 12, 2001, the disclosure of which isexpressly incorporated by reference herein.

1. Field of the Invention

The present invention relates to multi-row rolling mills, methods ofoperating these mills, and rolling equipment that uses the mills.

2. Description of Prior Art

Hot coils, the materials to be cold-rolled, are produced usinghot-rolling equipment. Under prior art, slabs 200 mm or more inthickness are cast by a continuous casting machine and these slabs arethen provided with unidirectional or reversing-type rolling by aplurality of pre-rolling mills to form bar materials. After these barmaterials have been further rolled to the required thickness by a tandemrolling mill group consisting of a plurality of continuously arrangedrolling mills, the bar materials are cooled by a cooling apparatus andwound by a coiler to form the hot coils mentioned above. Suchhot-rolling equipment intended for mass production is very large inscale.

In recent years, importance has been attached to the recycling of ironscraps, coupled with the occurrence thereof in great quantities, and thetendency for distributed arrangement of small-scale small-volumeproduction equipment, rather than integrated installation of large-scalelarge-volume production equipment, has been increasing. This tendencyhas resulted in construction of so-called “mini-hot” systems, namely,hot-rolling equipment up to about one million tons per annum in terms ofhot-coil production scale. With reference to the production capabilitiesof cold-rolling equipment, on the other hand, tandem rolling equipmentwith a continuous arrangement of four to five rolling mills is up toabout 1.5 million tons per annum in production volume, and the maximumproduction volume by single-stand reversing cold-rolling mills rangesfrom about 0.3 to 0.5 million tons per annum. For cold-rolling equipmentconnected to small-scale small-volume production equipment called the“mini-hot”, it is appropriate to have a production scale up to onemillion tons per annum. An example of an equivalent to such equipment isthe twin-stand tandem reversing mill described on page 144 of STEELTIMES APRIL 2000 (hereinafter, this mill is referred to as thetwin-stand reversing mill).

As set forth in Japanese Patent Application Laid-Open Publication No.Hei 9-239413, rolling equipment having at least two groups of rolls inone pair of housings, designed so as to enable rolling to be repeated atleast twice during one path, and capable of achieving a production scaleup to one million tons per annum by creating a high-pressure atmospherewithin a short time by use of a single-stand reversing mill(hereinafter, such equipment is referred to as the twin-reversing mill),has also become available.

SUMMARY OF THE INVENTION

For the twin-stand reversing mill, the material to be rolled is reeledout by tension reels arranged in front of and at the rear of apre-rolling machine and is then rolled by the main rolling machine whilebeing wound. The clearance between the two stands is as great as up toabout 5,000 mm, which is almost the same as that of a large-size tandemmill, and to ensure the proper arrangement of the machine components, adistance of about 5,000 mm also needs to be provided between the frontand rear tension reels and the main rolling machine. Accordingly, atotal of about 20 m of the entire thinned-down material which has beenwound into coil form after rolling, namely, about 10 m of the leadingand trailing ends each of the material, is not rolled to the desiredthickness and productivity decreases correspondingly. For the recenttypes of tandem rolling mills, since hot coils are connected upstream bywelding and then rolled continuously, their productivity is unevenbecause only the extremely narrow areas including the welded connectionsmay not be rolled to the desired thickness. The above-describedtwin-stand reversing mill, therefore, is extremely high in product lossratio. The twin-stand reversing mill, although better in productionyield than the single-stand reversing mill, is not sufficient inproduction volume, since the former mill does not does not have such astand-to-stand distance as provided in the latter mill.

For the twin-reversing mill, on the other hand, production yield can beimproved since the arrangement of one pair of roll groups in ahousing(s) enables the clearance between the roll groups to be reducedbelow 2,000 mm. Since the clearance between the roll groups of thetwin-reversing mill is short, human access to the roll groups in theevent of workpiece breakage or thinning-down trouble is difficult andoperations from removing the workpiece from the roll groups torecovering the corresponding machine components become time-consumingjobs, with the result that the rolling equipment decreases inavailability.

The present invention is intended to improve the recoverability of arolling mill from trouble by reducing the distance between roll groups.

A multi-row rolling mill based on the present invention is one having inone housing at least two groups of rolls including at least one pair ofwork rolls, and constructed so that when the workpiece to be rolled ispassed one time, it can be rolled using said respective work rolls,wherein the multi-row rolling mill is characterized in that it isprovided with a means for removing the workpiece if it stops movingbetween said roll groups.

A multi-row rolling mill based on the present invention according tocertain preferred embodiments has in one housing at least two groups ofrolls including at least one pair of work rolls, provided with acolumnar support member between said roll groups, and constructed sothat when the workpiece to be rolled is passed one time, it can berolled using said respective work rolls, wherein the multi-row rollingmill is characterized in that it is provided with a means for removingthe workpiece if it stops moving between said roll groups.

A rolling equipment system based on the present invention according tocertain preferred embodiments is characterized in that a multi-rowrolling mill having in one housing at least two groups of rollsincluding at least one pair of work rolls, constructed so that when theworkpiece to be rolled is passed one time, it can be rolled using saidwork rolls, and provided with a means for removing the workpiece if itstops moving between said roll groups, is applied to reversingcold-rolling equipment, or in that at least one such rolling mill isinstalled inside tandem rolling equipment.

A rolling equipment system based on the present invention according tocertain preferred embodiments is characterized in that in a multi-rowrolling mill having in one housing at least two groups of rollsincluding at least one pair of work rolls, constructed so that when theworkpiece to be rolled is passed one time, it can be rolled using saidrespective work rolls, and provided with a means for removing theworkpiece if it stops moving between said roll groups,

-   -   a first roll-side shifting unit movable in a rolling direction        and having at least two loading portions which can be loaded        with rolls is provided at the roll removal side of the multi-row        rolling mill, and    -   a second roll-side shifting unit movable in the rolling        direction and having at least two loading portions which can be        loaded with rolls is provided at the opposite side of said first        roll-side shifting unit in the multi-row rolling mill.

Rolling equipment based on the present invention according to certainpreferred embodiments is characterized in that in a multi-row rollingmill having in one housing at least two groups of rolls including atleast one pair of work rolls, constructed so that when the workpiece tobe rolled is passed one time, it can be rolled using said respectivework rolls, and provided with a means for removing the workpiece if itstops moving between said roll groups, a roll-side shifting unit movablein a rolling direction and having at least four loading portions whichcan be loaded with rolls is provided at the roll removal side of themulti-row rolling mill.

A multi-row rolling mill operating method based on the present inventionaccording to certain preferred embodiments relates to a multi-rowrolling mill which has in one housing at least two groups of rollsincluding at least one pair of work rolls and is constructed so thatwhen the workpiece to be rolled is passed one time, it can be rolledusing said respective work rolls, wherein the multi-row rolling milloperating method is characterized in that if the workpiece stops movingbetween said roll groups, removal of the workpiece will be accomplishedby broadening the clearance between one pair of work rolls included inat least one roll group.

A multi-row rolling mill operating method based on the present inventionaccording to certain preferred embodiments relates to a multi-rowrolling mill which has in one housing at least two groups of rollsincluding at least one pair of work rolls and is constructed so thatwhen the workpiece to be rolled is passed one time, it can be rolledusing said respective work rolls, wherein the multi-row rolling milloperating method is characterized in that if the workpiece stops movingbetween said roll groups, removal of the workpiece will be accomplishedby pulling out at least one of the upper rolls in at least one rollgroup to the outside of the rolling mill.

A multi-row rolling mill operating method based on the present inventionaccording to certain preferred embodiments relates to a multi-rowrolling mill which has in one housing at least two groups of rollsincluding at least one pair of work rolls, constructed so that when theworkpiece to be rolled is passed one time, it can be rolled using saidrespective work rolls, and provided with a through-plate guide forguiding the traveling of the workpiece between said roll groups, whereinthe multi-row rolling mill operating method is characterized in that ifthe workpiece stops moving between said roll groups, removal of theworkpiece will be accomplished by moving said through-plate guide fromthe position at which the traveling of the workpiece is to be guided, toany other position.

Other objects, advantages and novel features of the present inventionwill become apparent from the following detailed description of theinvention when considered in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front view of rolling equipment constructed according to afirst embodiment of the present invention.

FIG. 2 is a partial cross-sectional view of the rolling equipment ofFIG. 1.

FIG. 2A is a detailed view of a portion of the FIG. 2 equipment.

FIG. 3(a) is another partial cross-sectional view of the rollingequipment of FIGS. 1 and 2.

FIG. 3(b) is yet another partial cross-sectional view of the rollingequipment of FIGS. 1 and 2.

FIG. 4 is a top plan view of rolling equipment constructed according toanother embodiment of the present invention.

FIG. 5 is a plan view showing a roll replacement procedure according toa preferred embodiment of the invention.

FIG. 6 is another plan view showing a roll replacement procedureaccording to a preferred embodiment of the invention.

FIG. 7 is yet another plan view showing a roll replacement procedureaccording to a preferred embodiment of the invention.

FIG. 8 is an arrangement view of tandem rolling mills constructedaccording to another embodiment of the invention.

FIG. 9 is another arrangement view of tandem rolling equipmentconstructed according to an embodiment of the present invention.

FIG. 10 is yet another arrangement view of tandem rolling equipmentconstructed according to an embodiment of the present invention.

FIG. 11 is a partial cross-sectional view of a rolling mill whose workroll bearing box has a bending force assigning section located near thematerial to be rolled constructed according to an embodiment of theinvention.

FIG. 12 is a partial cross-sectional view showing a pass line adjustmentmechanism constructed according to an embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

Description of Embodiments

The above mentioned problems can be solved according to the invention byfacilitating removal of the workpiece after rolling has stopped with theworkpiece intervening between the roll groups.

A through-plate guide is provided in the rolling direction of theworkpiece (namely, a direction almost vertical to the travelingdirection of the workpiece) between two rows of roll groups, and atleast one roll group is opened so that even if rolling stops with theworkpiece intervening between the roll groups, the resulting clump ofworkpiece can be passed through the rolls. Accordingly, the workpiececan be removed from the open side.

Since a movable bender for assigning bending force is provided at thebearing box of the work rolls, since this bender has push-pullstructure, and since the engagement section between the bender and thebearing box of the work rolls is distanced so as to be verticallysymmetrical with respect to the center of pass of the workpiece, thework rolls can have a great opening allowance and it is also possible toprevent the work rolls from becoming caught at the workpiece between theroll groups when the rolls are removed from the rolling mill. Withfurther reference to the engagement section of the bearing box whichassigns bending force to the work rolls, in the case that thisengagement section is located near the workpiece, the correspondingengagement section may not only restrict the opening operation of thework rolls in the direction opposite to the workpiece, but also protrudeduring removal of the rolls when the engagement section moves in theaxial direction of the rolls in the rolling mill. Even if these eventsactually occur, however, the problem that the possible interference withthe workpiece left between the roll groups may obstruct removal of therolls can also be avoided.

With reference to at least one group (row) of rolls, at least one of theabove-mentioned middle rolls or reinforced rolls in the rolling mill,except for the pair of work rolls, is constructed so as to be removablefrom the mill. In addition, a rail for removing the upper middle roll isprovided and this rail can also be used to remove the upper reinforcedroll when at least one of the two work rolls is moved. Hereby, even ifthe workpiece gets caught between the work rolls and the through-plateguide and prevents the work rolls from being removed, the rolls at rearcan be removed and this makes the narrow section accessible for manualremoval of the corresponding workpiece. For a conventional rolling mill,the lower reinforced roll has a table mounted on its bearing portion andthe bearing portion of the upper reinforced roll is further mounted onthis table, with the result that the upper reinforced roll can beinserted into and removed from the rolling mill. In this case, it isabsolutely necessary to remove the work rolls beforehand, and the upperreinforced roll cannot be removed unless the work rolls can be removed.In the present invention, however, such a problem can be avoided.Furthermore, since the pull-out rail for the upper middle roll isconstructed so as to be usable for the upper reinforced roll, it ispossible to remove the upper reinforced roll without installing aspecial unit.

The through-plate guides between at least two sets of roll groups areconstructed so as to be capable of withstanding the shock of platerupture, and at least one of two through-plate guides has movablestructure to enable removal of the workpiece even if it is left betweentwo pairs of work rolls and the through-plate guides in the event ofrolling trouble. Although rolling is associated with rolling troublesuch as plate rupture or plate thinning-down, since the spaces betweenrolls and through-plate guides cannot be made as spacious as in thetwin-stand reversing mill, the plate material will confinedly lodge ineither such space if rolling trouble actually happens. At that time, thedriving force of the rolling motor, the inertial force of the workpiece,and/or other significant shocks will be exerted on the through-plateguides. The through-plate guides are therefore constructed so as to becapable of withstanding the shocks. Also, the material, even if leftbetween roll groups, can be removed by making at least one of the twothrough-plate guides movable and moving that guide so as to spread thecorresponding space.

Since, at the roll removal side, two roll-side shifting units arearranged, one in front and one at rear, or one roll-side shifting unitis provided that enables at least four rows of roll groups to bearranged, it is possible to simultaneously change rolls between morethan one pair of roll groups and to change either one pair of rollgroups independently. Despite adjacent arrangement of the roll groups,therefore, roll changing operations equivalent to those of thetwin-stand reversing mill are possible.

At least one multi-row rolling mill of the above-described configurationhas been applied to the interior of a reversing cold-rolling mill ortandem rolling mill, in particular. In the case of a reversingcold-rolling mill, although portions not up to the desired thicknessexist at both the leading and trailing ends of each coil, productionyield can be improved since the clearances between roll groups can bereduced. In addition, the number of housings required can be reduced toone pair only and installation costs can also be saved moresignificantly than in the case of the twin-stand reversing mill. A largeportion of tandem rolling mills are serialized and since they are of theunidirectional rolling type, although they are very high in yield, theyare extremely large in scale and high in installation costs. Theapplication of the above-described multi-row rolling mill, and itsoperating method, to at least one portion of such a tandem rolling millenables space saving in addition to the implementation of an inexpensivetandem rolling mill.

Reducing the distance between roll groups in this way minimizes thewaste of product coils, facilitates human access for removal of brokenworkpieces, and thus minimizes machine component recovery time. Theequipment itself can also be made compact and this enables space savingand inexpensive installation.

(Embodiment 1)

An embodiment of the present invention is described below usingdrawings. FIG. 1 is a front view of a multi-stage rolling millconstructed according to a first embodiment of the invention.

The multi-stage rolling mill shown in FIG. 1 has two roll groups, “a”and “b”. The first roll group comprises an upper reinforced roll 1 a, anupper middle roll 2 a, an upper work roll 3 a, a lower work roll 4 a, alower middle roll 5 a, and a lower reinforced roll 6 a. The second rollgroup comprises an upper reinforced roll 1 b, an upper middle roll 2 b,an upper work roll 3 b, a lower work roll 4 b, a lower middle roll 5 b,and a lower reinforced roll 6 b. The arrangement with these two rollgroups consisting of six stages is taken as an example in the followingdescription of the first embodiment.

The two roll groups in this rolling mill are contained and accommodatedin a housing 7. A deflector roller 8, a tension reel 9, and a frame 10for supporting the deflector roller and the tension reel, are arrangedin the rolling direction on both sides in the mill. That is to say,tension reel 9 is located on both sides of the multi-stage rolling mill.

A coil-like workpiece 11 is sent, as coil workpiece 11 a, from onetension reel 9 via the multi-stage rolling mill to the other tensionreel 9, where the workpiece is then wound as coil workpiece 11 b. Duringthis process, workpiece 11 is rolled using the upper and lower pairs ofroll groups: upper work roll 3 a, lower work roll 4 a, upper work roll 3b, and lower work roll 4 b.

At the bottom of the pass line in housing 7, a lower through-plate guide12 (12 a, 12 b) and a tension roller 13 are arranged to guide theworkpiece 11, and at the top of the pass line, an upper entrance guide14 a, an exit guide 14 b, and an upper through-plate guide 15 arearranged. Also, a center post 16 is provided as a columnar member in thecenter of housing 7 in the rolling direction, between the two rollgroups. The clearance between the two roll groups can be reduced byadopting such configuration.

In addition, a roll group clearance adjustment mechanism is provided atthe top of the roll groups as shown in, for example, FIG. 12. Anotheradjustment mechanism is also provided between an upper reinforced rollchock 21, which functions as a bearing for upper reinforced roll 1 a,and housing 7. Between upper reinforced roll chock 21 and housing 7, arocker plate 61 is provided at the top of upper reinforced roll chock21, and an adjustment block 62 is provided at the top of rocker plate61, and a stepped rocker plate 63 and an inclined rocker plate 64 arearranged at the top of adjustment block 62. Inclined rocker plate 64engages with an inclined block installed on housing 7. A cylinder 67, acylinder 68, and other driving components are provided for steppedrocker plate 63 and inclined rocker plate 64 each in order to move theserocker plates in the axial direction of the rolls, and the verticalposition of upper reinforced roll 1 a can be adjusted by adjusting thepositions of stepped rocker plate 63 and inclined rocker plate 64 in theaxial direction of the rolls by use of cylinders 67 and 68. Verticaladjustment of upper reinforced roll 1 a enables height adjustment of theupper portions of the roll groups (namely, pass line adjustment), andthe adjustment of the clearance between one pair of work rolls.

Next, an enlarged cross-sectional view showing the center of a rollingmill based on the present invention is shown as FIG. 2. This figure alsoshows the machine configuration between two roll groups.

As shown in FIG. 2, an upper middle roll bending block 17, anupper/lower work roll bending block 18, a lower middle roll bendingblock 19, and a lower middle roll changing rail 20 are arranged atcenter post 16. An upper reinforced roll chock 21, an upper middle rollchock 22, an upper work roll chock 23, a lower work roll chock 24, alower middle roll chock 25, and a lower reinforced roll chock 26 aremounted at the operating end (roll removal side) and driving end of eachroll.

FIG. 2 only shows the right-half or left-half of the roll center line ofeach roll group, and each bending block and other related components arearranged symmetrically with respect to the roll center line of each rollgroup.

Upper middle roll bending block 17 is equipped with a connecting rod 27a at both the operating end and driving end thereof, and a roll changingrail 28 is provided at a portion of the connecting rod. Lower middleroll bending block 19 is also equipped with a connecting rod 27 b atboth the operating end and driving end thereof, and a roll changing rail28 is provided at a portion of the connecting rod.

Upper/lower work roll bending block 18 also has an upper work rollchanging rail 47 at a portion thereof, and the upper work roll 3 a, whenin engagement with a roll changing wheel 35 provided at upper work rollchock 23, can be removed from the operating end of the rolling millindependently.

Upper through-plate guide 15 is driven vertically by a vertical drivingcylinder 29. The movement of this guide is stopped by a stopper 30.

In this embodiment, an upper through-plate guide 15 a and an upperthrough-plate guide 15 b are provided at the “a” side and “b” side,respectively, of the roll groups. One end of upper through-plate guide15 a, for example, is located for the desired clearance with respect tothe outer surface of upper work roll 3 a, and the other end is mountedon center post 16 so as to work as the rotational fulcrum of the upperthrough-plate guide 15 a. The top end of upper through-plate guide 15 ahas a cylinder 29, one end of which is mounted on center post 16 and theother end is connected to upper through-plate guide 15 a. The operationof the cylinder 29 rotates the other end of upper through-plate guide 15a as a rotational fulcrum. Upper through-plate guide 15 b has a similarconstruction. More specifically, cylinder 29 mentioned above is providedas the shifting unit that moves upper through-plate guide 15 from theposition at which the traveling of the workpiece is to be guided, to anyother position. Since there is provided at least one upper through-plateguide 15 having a lift, this guide enables appropriate response to thestoppage of workpiece 11.

The arrangement with both a worm gear 31, which meshes with stopper 30,and a worm gear 32, which further meshes with work gear 31, allows thepositioning of stopper 30. A portion of upper through-plate guide 15 hasa receiving face 33, which engages with stopper 30.

Also, upper through-plate guide 15 is mounted on center post 16. Since,in this way, upper through-plate guide 15 is installed on center post16, not at the roll bearing box, the equipment permits easy maintenanceand its structure can be simplified. That is to say, the roll bearingbox usually requires roll replacement associated with the surfacefriction of the rolls, and the roll bearing box and the rolls arereplaced frequently in integrated form. For this reason, a plurality ofroll sets (roll bearing boxes and rolls) exist and are used each time.To install upper through-plate guide 15 on each roll bearing box,therefore, it is necessary to install this guide for each roll set, andas a result, installation costs increase. The installation of upperthrough-plate guide 15 on each roll bearing box also inconveniencesmaintenance. In this embodiment, since upper through-plate guide 15 isinstalled on center post 16 of the rolling mill, not at the roll bearingbox, the equipment permits easy maintenance and its structure can besimplified.

For normal rolling conditions, it is desirable that as shown in FIG. 2,one end of upper through-plate guide 15 should be slightly distancedfrom the outer surface of upper work roll 3 a. Workpiece 11 can beguided smoothly between upper and lower work rolls 3 a and 4 a, androlled, by positioning one end of upper through-plate guide 15 that way.It is also desirable that there be provided a mechanism by which theclearance from the outer surface of upper work roll 3 a can be adjustedto the desired value according to the particular operating diameter ofthe work rolls. For example, it is possible to set one end of upperthrough-plate guide 15 easily to a position close to the outer surfaceof upper work roll 3 a, or to achieve follow-up with the operatingdiameter of the work rolls, by providing a lift that drives upperthrough-plate guide 15 vertically.

During this phase, in case of trouble due to an unusual event such asplate breakage, workpiece 11 stops moving between lower through-plateguide 12 and upper through-plate guide 15, and consequently, the rollingproduction operations are stopped. This event also occurs between thetwo stands of the twin-stand reversing mill. The workpiece that hasstopped moving needs to be removed for early recovery from such asituation.

First, the work rolls need to be opened in the direction opposite toworkpiece 11. Next, workpiece 11 that has stopped moving is to beremoved towards tension reel 9. Under some specific states of thecorresponding workpiece 11, it can be removed by conducting theseoperations. Workpiece 11 can be removed by, for example, increasing theclearance between the upper and lower work rolls 3 a and 4 a of one rollgroup by use of the roll group clearance adjustment mechanism first andthen pulling the workpiece out through the increased clearance.

However, the following method is required if the way the work rolls areclogged with workpiece 11 is too tough for its removal using the methoddescribed above. That is to say, roll changing wheel 35 which has upperwork roll 3 a positioned at upper work roll chock 23 is to be traveledalong work roll changing rail 47 and then the workpiece is to be removedtowards the operating side of the rolling mill independently. FIG. 3(a)is an explanatory view of a rolling mill whose upper work roll 3 a wasremoved from one of the roll groups shown in FIG. 2. Removal of upperwork roll 3 a from the rolling mill creates a sufficient clearancebetween upper middle roll 2 a and lower work roll 4 a, thus enablingeasy removal of the workpiece 11 that has stopped.

After that, the workpiece 11 that has stopped can be removed by movingstopper 30 upward and then also moving upper through-plate guide 15 byuse of vertical driving cylinder 29. The vertical operation of upperthrough-plate guide 15 enables space adjustment and, hence, easy removalof the workpiece 11 that has stopped. In other words, the space forremoval can be reserved by sliding upper through-plate guide 15 out fromthe guiding position to the desired position and moving the guide awayfrom the guiding area. Equipment structure can be simplified byincluding, in the machine configuration of this embodiment, the meansfor sliding upper through-plate guide 15 out from the guiding positionto the desired position and moving the guide away from the guiding area.

The removal space can be further spread by moving tension roller 13downward for easier removal. More specifically, removal can be furthersimplified by proving a vertical driving unit, such as a cylinder, thatmoves tension roller 13 vertically.

FIG. 3(b) is an explanatory view of a rolling mill whose upper middleroll 2 a was removed from one of the roll groups shown in FIG. 2. Upperwork roll 3 a may not be readily removable if workpiece 11 has stoppedmoving between upper work roll 3 a and upper through-plate guide 15. Inthat case, both upper middle roll 2 a and upper middle roll chock 22 areto be lifted together by operating middle roll bending cylinder 34 andthen roll changing wheel 35 is to be traveled along rail 28 a to removeupper work roll 3 a. In this way, upper work roll 3 a can be removed bycreating a space at upper middle roll 2 a, then making access to theequipment, and manually cutting a portion of workpiece 11. Once theupper work roll has thus been removed, it will be possible, as shown inFIG. 3(a), to create a clearance between upper and lower work rolls 3and 4 by lifting upper through-plate guide 15 and then to remove theworkpiece 11 that has stopped. If the space at upper middle roll 2 adoes not suffice, a sufficient space can be obtained by pulling upperreinforced roll 1 a out along roll changing rail 28.

In this way, it is possible to obtain a workpiece removal space byremoving the desired roll or by sliding upper through-plate guide 15from the guiding position to any other position and moving this guideaway from the guiding area, and then to remove easily the workpiece 11that has stopped moving inside the rolling mill.

It is desirable that lower through-plate guides 12 b and 12 c and upperthrough-plate guide 15 should have highly rigid structure so as not toget deformed against shocks due to plate rupture or other unusualevents.

(Embodiment 2)

FIG. 4 is a plan view showing another embodiment of the presentinvention. The equipment in this embodiment comprises motors 38 a and 38b for rotationally driving rolls, reduction gears 39 a and 39 b forobtaining a suitable rotational speed, and spindles 40 a and 40 b fortransmitting a torque to the rolls. These components drive the rollsrotationally for workpiece rolling operations.

Both tension reels 9 a and 9 b have a driving motor 41 a or 41 b and adriving spindle 42 a or 42 b, and these components give suitable tensionto workpiece 11 for its rotational driving.

In the equipment, a roll changing unit for rapidly changing therespective rolls of two roll groups is provided at the operating side ofthe rolling mill, namely, the opposite side of its driving means.

For this roll changing unit, a coil placement table 43 a or 43 b forworkpiece 11 is provided at both sides of the rolling direction, at theoperating side of the rolling mill. For this reason, side shifting cartsA44 and B45 for roll changing are also provided in front and at rear.The rolling mill driving means, the rolling mill, and side shiftingcarts A44 and B45 for roll changing are arranged in that order in thelateral direction of the workpiece. Push-pullers 46 a and 46 b that pushand pull out the respective rolls of the roll groups for removal andinsertion, respectively, are further arranged for roll changing.

Embodiments of the roll replacement methods using the equipment of FIG.4 are described below. Rolls can be replaced by changing two roll groupsat the same time or by replacing one roll group. These methods aredescribed below using FIGS. 5 and 6, respectively.

FIG. 5 is an explanatory view showing the method of changing two rollgroups at the same time. This method comprises a first process, a secondprocess, a third process, and a fourth process. Symbol O in FIG. 5denotes an old roll, and likewise, symbol N denotes a new roll.

The method where the circle-marked old rolls in the rolling mill are tobe replaced for reasons such as roll surface roughness or unusual wear,is as follows:

In the first process, before rolling is completed, new rolls (N) areplaced at the positions shown in the figure, on roll-changing sideshifting carts A44 and B45, and then rolling is completed. Next, in thesecond process, push-puller 46 is moved forward and backward and the oldrolls (O) are pulled out onto roll-changing side shifting carts A44 andB45. After this, in the third process, the side shifting carts are movedto move the new rolls (N) to the centers of the respective roll groups.Finally, in the fourth process, the respective roll groups arere-inserted into the rolling mill by moving push-puller 46 forward tocomplete the insertion of the new rolls (N), and then push-puller 46 isreversed to return to the position existing when the first process wasperformed.

As described above, simultaneous roll replacements between two rollgroups can be easily performed using the above method.

FIG. 6 is an explanatory view showing the method of replacing one rollgroup. In this case, roll-changing side shifting cart B45, for example,is not used. In the first process, before rolling is completed, a newroll (N) is placed on roll-changing side shifting cart A44, and thenrolling is completed. Next, in the second process, push-puller 46 ismoved forward and backward and the old roll (O) is pulled out ontoroll-changing side shifting cart A44. After this, in the third process,the side shifting cart is moved to move the new roll (N) to the centerof the corresponding roll group. Finally, in the fourth process, theroll group is re-inserted into the rolling mill by moving push-puller 46forward to complete the insertion of the new roll (N), and thenpush-puller 46 is reversed to return to the position existing when thefirst process was performed. The forward/backward movement stroke ofpush-puller 46 in this case is shorter than in the case that two rollgroups are replaced at the same time.

FIG. 7 is an explanatory view showing the roll replacement method thatuses one side shifting unit. In this figure, roll-changing side shiftingcart C48 has the structure that enables four rows of roll groups to bearranged. In the first process, before rolling is completed, new rolls(N) are placed on roll-changing side shifting cart C48, and then rollingis completed. Next, in the second process, push-puller 46 is movedforward and backward and the old rolls (O) are pulled out ontoroll-changing side shifting cart C48. After this, in the third process,side shifting cart C48 is moved to move the new rolls (N) to the centersof the respective roll groups. Finally, in the fourth process, therespective roll groups are re-inserted into the rolling mill by movingpush-puller 46 forward to complete the insertion of the new rolls (N),and then push-puller 46 is reversed to return to the position existingwhen the first process was performed. Replacement of one roll group usesa portion of the side guides and occurs as shown in FIG. 6.

(Embodiment 3)

FIG. 8 is a view of a conventional tandem rolling mill. Similarly, FIG.9 is a view showing an example in which a multi-row rolling mill basedon the present invention is applied to a tandem rolling mill, and FIG.10 is a view showing another example in which a multi-row rolling millbased on the present invention is applied to a tandem rolling mill. Forthe purpose of comparison with a conventional four-stand tandem rollingmill, the overall lengths of the three types of equipment are shown asL1, L2, and L3, in the figures. The stand-to-stand distance in FIG. 8 is5 m, whereas that of the multi-row rolling mill is 1.8 m. Hence, theequipment in the case of L2 can be reduced to a length 3.2 m shorterthan in the case of L1, and L3 is 6.4 m shorter, which indicates thatthe equipment can be reduced by 42.7% in length.

Although all the above-described embodiments of the present inventionapply to the case that the rolling mill has six stages of roll groups,the same also applies to a four-stage rolling mill and a six-stagerolling mill. Also, although the above embodiments relate tocold-rolling mills, the art of the present invention can also be appliedto hot-rolling mills. Application to cold-rolling mills, however, isexpected to produce more significant effects.

Bending cylinder 37 in upper/lower work roll bending block 18 usuallyperforms increase bending and decrease bending operations duringrolling. During increase bending, no problems arise since upper workroll chock 23 is pushed upward as shown in FIG. 2. During decreasebending, however, since upper work roll chock 23 is pushed downward, theresulting clearance between upper work roll chock 23 and bendingcylinder 37 creates the undesirable situation that a dead zone inbending operation occurs during increase/decrease bending modeselection. The occurrence of this dead zone in bending operation can beprevented by providing a special bending cylinder 37 a for pushing and aspecial bending cylinder 37 b for pulling. See the detailed view ofsection C-C′ in FIG. 2A.

FIG. 11 is a view showing the case that the bending force assigningsection of the work roll bearing box is located near the material to berolled. Upper work roll chock 23 has collar portions 301 and 302 forreceiving the bender, and lower work roll chock 24 also has collarportions 401 and 402 for receiving the bender. The presence of thecollar portions 301 and 401 becomes a problem. Collar portion 301becomes a restriction on the trade-offs with upper/lower work rollbending block 18 when the upper work roll is lifted. Also, when thiscollar portion is present, the structure of upper through-plate guide 15becomes complex since this upper through-plate guide needs to beretracted during removal of the work rolls from the rolling mill. Inaddition, even if the upper through-plate guide has successfully beenretracted, if the workpiece is left between roll groups, the rolls maynot be removable because of their possible interference with thecorresponding collar portion. Collar portion 401 also creates a similarundesirable situation. It is preferable, therefore, that as shown inFIG. 2A, the bender for assigning bending force to the work roll bearingbox should be of push-pull structure and that the engagement sectionbetween the bender and the work roll bearing box should be distanced soas to be vertically symmetrical with respect to the center of pass ofthe workpiece. When only the increase bender is required, push-pull isnot required and only pushing is required.

Although the push-puller 46 (46 a, 46 b) that pushes and pulls out therespective rolls of the roll groups for removal and insertion,respectively, may use a hydraulic cylinder type, a motor-driven carttype, or the like, any such type of push-puller can be applied.

According to the embodiments described above, product yields can beimproved by reducing the clearance between two groups of rolls. Also,even in case of trouble such as the rupture of the workpiece, theavailability of the rolling equipment also improves since its componentscan be recovered rapidly. In addition, space saving and reduction ininstallation costs can be achieved.

The present invention yields the effect that the recoverableness of therolling mill from rolling trouble can be improved by reducing thedistance between roll groups.

The foregoing disclosure has been set forth merely to illustrate theinvention and is not intended to be limiting. Since modifications of thedisclosed embodiments incorporating the spirit and substance of theinvention may occur to persons skilled in the art, the invention shouldbe construed to include everything within the scope of the appendedclaims and equivalents thereof.

1. A multi-row rolling mill having in one housing at least two groups ofrolls, each group including at least one pair of work rolls, providedwith a columnar support member between said roll groups, and constructedso that by one pass of a workpiece, the workpiece can be rolled by saidrespective work rolls, wherein the multi-row rolling mill ischaracterized by comprising a removal supporting means between said rollgroups in said housing for facilitating removal of a work piece stoppedbetween said roll groups said removal supporting means comprising:through-plate guides arranged along a workpiece traveling direction sothat one end of one of said through-plate guides face the work roll ofone of said roll groups and one end of the other through-plate guidefaces the work roll of the other roll group, and disposed at a firstposition spaced a first distance from said respective work rolls, forguiding traveling of said work piece between said roll groups duringrolling operation, and a unit for moving respective ones of saidthrough-plate guides, from said first position to a second position tobroaden a space for removal of said work piece, wherein saidthrough-plate guides for guiding said workpiece each are mounted on saidcolumnar support member at an end thereof opposite to said end facingsaid work roll, and wherein said unit being for independently movingsaid through-plate guides so that said end of at least one of saidthrough-plate guides, facing said work roll, moves from said firstposition to said second position.
 2. A multi-row rolling mill as setforth in claim 1, wherein the multi-row rolling mill is characterized inthat a movable bender for assigning bending force is provided at a rollchock of said work rolls and in that an engagement section between saidbender and said roll chock is disposed so as to be verticallysymmetrical with respect to a center of pass of the workpiece.
 3. Amulti-row rolling mill as set forth in claim 1, wherein the multi-rowrolling mill is characterized in that at least one of the groups ofrolls consists of one pair of work rolls, one pair of middle rolls forsupporting said pair of work rolls, and one pair of reinforced rolls forsupporting said pair of middle rolls, and in that a pull-out rail isprovided so that under a status that at least one roll of said pair ofwork rolls is left inside the rolling mill, at least one of said middlerolls or reinforced rolls, other than the other work roll left insidethe rolling mill, can be pulled out to the outside of the mill.
 4. Amulti-row rolling mill as set forth in claim 1, wherein the multi-rowrolling mill is characterized in that said through-plate guides each aremounted on said columnar support member located between said roll groupsand independently movable by said unit.
 5. A multi-row rolling millhaving in one housing at least two groups of rolls, each group includingat least one pair of work rolls, and a columnar support member betweensaid roll groups, and constructed so that by one pass of a workpiece tobe rolled, the workpiece can be rolled by said respective work rolls,wherein a removal supporting means for facilitating removal of aworkpiece stopped between said roll groups is mounted on said columnarsupport member, said removal supporting means comprising through-plateguides, arranged between said roll groups along a workpiece travelingdirection so as to be spaced from said respective work rolls, forguiding said workpiece between said at least two roll groups, and amoving mechanism for moving sad through-plate guides independently fromeach other to enlarge a space for the removal of the workpiece, andwherein said through-plate guides each are mounted on said columnarsupport member to be movable around a supported portion thereof, saidthrough-plate guides each having an end close to one of said work rolls,and said moving mechanism is constructed to move said ends of saidthrough-plate guides so as to extend said space for the workpiece byrotation of at least one of said through-plate guides.